Referral tracking promotion software?

I’m looking to do a pre-launch campaign and would like to do a signup offer where everyone who submits their email address gets 10% off during our grand opening entered for a chance to win a prize. I would like to incentivize the offer by increasing their discount and their chances of winning a prize for every pre-launch referral entry.

It doesn’t have to be exactly that, but at least accomplish the idea.

Can anyone recommend any web software solution I can look into for managing this campaign for us?